Taxanes are diterpene compounds which find utility in the pharmaceutical field. For example, paclitaxel (Taxol.RTM.), a taxane having the structure: ##STR1## where Ph is phenyl, Ac is acetyl and Bz is benzoyl, has been found to be an effective anticancer agent. Naturally occurring taxanes such as paclitaxel may be found in plant materials, and have been isolated therefrom. Such taxanes may, however, be present in plant materials in relatively small amounts so that, in the case of paclitaxel, for example, large numbers of the slow-growing yew trees forming a source for the compound may be required.
Although certain semi-synthetic routes for the preparation of taxanes such as paclitaxel and analogs thereof have been described, more efficient methods continue to be sought in the art. In this regard, routes are sought for the preparation of intermediates useful in forming the C-13 sidechain of pharmaceutically useful taxanes, particularly such compounds having a desired stereoconfiguration.